However, not only the highlighted syllable is growing and shrinking, but the whole line is always jumping in time with the growth of the syllables. You can see this in one of my videos right here: https://www.youtube.com/watch?v=Hkaw4AeHTuQ

Since I'm only using \fscy120 and \fscy100, I'm not sure how to remove the jumping. =( Do you have any idea how to solve this problem? Any idea appreciated!